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Large-scale electron acceleration by parallel electric fields during magnetic reconnection
Egedal, J.; Daughton, W.; Le, A.
Magnetic reconnection is a process by which the field lines of a magnetized plasma undergo dramatic realignment, releasing large amounts of energy. Large-scale simulations of reconnection events in the Earth's magnetosphere suggest that this process takes place over much greater distances than previously expected.
Fundamental Properties of Stars Using Asteroseismology from Kepler and CoRoT and Interferometry from the CHARA Array
Kawaler, S. D.; Thompson, M. J.; Christensen-Dalsgaard, J. +37 more
We present results of a long-baseline interferometry campaign using the PAVO beam combiner at the CHARA Array to measure the angular sizes of five main-sequence stars, one subgiant and four red giant stars for which solar-like oscillations have been detected by either Kepler or CoRoT. By combining interferometric angular diameters, Hipparcos paral…
Evidence for ultrafast outflows in radio-quiet AGNs - III. Location and energetics
Cappi, M.; Tombesi, F.; Reeves, J. N. +1 more
Using the results of a previous X-ray photoionization modelling of blueshifted Fe K absorption lines on a sample of 42 local radio-quiet AGNs observed with XMM-Newton, in this Letter we estimate the location and energetics of the associated ultrafast outflows (UFOs). Due to significant uncertainties, we are essentially able to place only lower/upp…
The Evolution of Solar Flux from 0.1 nm to 160 µm: Quantitative Estimates for Planetary Studies
Meadows, Victoria S.; Cohen, Martin; Catling, David C. +3 more
Understanding changes in the solar flux over geologic time is vital for understanding the evolution of planetary atmospheres because it affects atmospheric escape and chemistry, as well as climate. We describe a numerical parameterization for wavelength-dependent changes to the non-attenuated solar flux appropriate for most times and places in the…
Energetic galaxy-wide outflows in high-redshift ultraluminous infrared galaxies hosting AGN activity
Ivison, R. J.; Smail, Ian; Alexander, D. M. +10 more
We present integral field spectroscopy observations, covering the [O III] λλ4959, 5007 emission-line doublet of eight high-redshift (z = 1.4-3.4) ultraluminous infrared galaxies (ULIRGs) that host active galactic nucleus (AGN) activity, including known submillimetre luminous galaxies. The targets have moderate radio luminosities that are typical o…
Sizes and Surface Brightness Profiles of Quiescent Galaxies at z ~ 2
van Dokkum, Pieter G.; Franx, Marijn; Szomoru, Daniel
We use deep Hubble Space Telescope Wide Field Camera 3 near-infrared imaging obtained of the GOODS-South field as part of the CANDELS survey to investigate a stellar mass-limited sample of quiescent galaxies at 1.5 < z < 2.5. We measure surface brightness profiles for these galaxies using a method that properly measures low surface brightnes…
Enhanced star formation rates in AGN hosts with respect to inactive galaxies from PEP-Herschel observations
Berta, S.; Magnelli, B.; Nordon, R. +35 more
We compare the average star formation (SF) activity in X-ray selected AGN hosts with a mass-matched control sample of inactive galaxies, including both star forming and quiescent sources, in the 0.5 < z < 2.5 redshift range. Recent observations carried out by PACS, the 60-210 µm photometric camera on board the Herschel Space Observator…
A far-infrared survey of bow shocks and detached shells around AGB stars and red supergiants
Blommaert, J. A. D. L.; Jorissen, A.; Ottensamer, R. +16 more
Aims: Our goal is to study the different morphologies associated to the interaction of the stellar winds of AGB stars and red supergiants with the interstellar medium (ISM) to follow the fate of the circumstellar matter injected into the interstellar medium.
Methods: Far-infrared Herschel/PACS images at 70 and 160 µm of a sample of…
Dissipationless Formation and Evolution of the Milky Way Nuclear Star Cluster
Mastrobuono-Battisti, Alessandra; Merritt, David; Antonini, Fabio +1 more
In one widely discussed model for the formation of nuclear star clusters (NSCs), massive globular clusters spiral into the center of a galaxy and merge to form the nucleus. It is now known that at least some NSCs coexist with supermassive black holes (SMBHs); this is the case, for instance, in the Milky Way. In this paper, we investigate how the p…
An over-massive black hole in the compact lenticular galaxy NGC 1277
van der Wel, Arjen; Gebhardt, Karl; van de Ven, Glenn +3 more
Most massive galaxies have supermassive black holes at their centres, and the masses of the black holes are believed to correlate with properties of the host-galaxy bulge component. Several explanations have been proposed for the existence of these locally established empirical relationships, including the non-causal, statistical process of galaxy…